The tournament AI in Mount & Blade apparently decides that the best way to win is to drive into a wall. And then get fenced in by dismounted horses.
The AI will move up in sieges in a terribly disorganized yet straightforward fashion, causing them to often accidently push you, their commanding officer, off the ladder, which may result in serious fall damage, while they themselves are all too eager to get massacred at the choke point above, often without even getting a hit in. The best way to handle this is to go first.
Similarly, the AI in sieges and normal battles alike will waste their very powerful lords and cavalry units on a first charge of their own instead of keeping them in reserve to use them when they'd actually be able to inflict serious damage while your forces are clashing with the main army.
This is also why Fragile Speedster forces, especially the Khergit Khannate, and Lance Cavalry in general, are basically worthless in the hands of an AI player. the AI only knows how to ram things head on, and once in there, has the cavalry basically slow down and engage the infantry by like Cataphracts, rather than going through and then slamming in again like Knights.
The famous Game Mod The Eagle And Radiant Cross, which puts the game in a Renaissance setting, adding firearms and such, has a unit type which uses a hand cannon, a scripted weapon that has terrible accuracy, but can kill entire swarms of enemies with one well-placed shot, making it the bane of formations and tightly packed enemy hordes. The problem is that they will use this highly dangerous weapon as if it was a regular rifle. This means that not only will they miss out on chances to deal big damage, such as firing on a small group of enemies instead of a huge crowd, or even trying to unsuccessfully hit a single cavalryman circling them while a much bigger formation of swordfighters is closing in to turn them into dead meat; but they also will carelessly fire this weapon into their own ranks, often killing fellow allies in the battle or even the Cannoneer next to them because they had to shoot diagonally, if you're not careful, they will also shoot down you, again, their own commanding officer. It's quite telling that one of the most efficient tactics to use this weapon properly is to take a few of your Cannoneers into battle, then immediately execute one of them by shooting him in the head, then picking up his hand cannon and using it yourself to actually hit the enemy army where it really hurts.
The AI won't attack groups that significantly outnumber it. It also prioritizes taking out weaker groups, such as a lord with half as many troops as usual. This can cause the AI to go into a loop where it sees a weak lord, moves in to attack, and runs away when it gets close because another enemy group nearby outnumbers the AI. Once the AI gets far enough away that the larger group isn't a threat, it tries to go after the smaller group all over again. The only way to stop this is to convince the AI to follow you instead. If you are supposed to follow that AI as a quest, you most likely don't have the stats to do this and are forced to wait for them to do this or you fail the quest.
It's possible for lords to ignore castles or towns that are relatively unguarded. This is because the lord isn't strong enough by themselves to decisively take the castle. Instead of asking for the player / other lords to help them take the castle, they will waste the opportunity and let the settlement replenish its defenses. In fact, only the Marshall of each faction will ask you to follow them, so if that specific lord wants to wait in town instead, it's impossible for your faction to gather enough troops to take down most settlements.
One of the chief reasons why it's practically impossible to not kill any civilians by accident while actively avoiding contact in a ground vehicle in [PROTOTYPE]. It seems like once you induced panic in them, they'll abandon almost all of their reliance on their senses. That's also assuming you aren't convinced of their intention to commit suicide in the face of the game's setting.
Oh, Prototype. Thou art a shining example of this trope. Where civilians show absolutely no regard for their own safety, the most dangerous thing a Marine can face is another Marine and where highly-trained military personnel can TD Dance off of a platform to their deaths. It makes you a bit less guilty for killing them, because they genuinely come across as Too Dumb to Live.
The slightest disruption in traffic flow can cause huge pile ups. Tanks will just drive over anything in the way.
Soldiers will charge in the direction of any loud sound that they hear - such as Alex landing on concrete hard enough to cause a small crater. However, even if Alex is the only one around and standing in the middle of the crater, they won't suspect him at all if he's in a military disguise. On top of that, if this is done close enough to water, it's quite likely that soldiers (who can't swim) will dive right off the island in their zeal to find Alex, crossing this trope with Too Dumb to Live.
Later in the game, you can accuse a random soldier of being you in a military base. Not only do the military always believe random accusations from a rank and file soldier, even if the same guy made the accusation 15 times already, but they always open fire. Even if they are holding a rocket launcher and standing next to the target in question.
No matter how powerful the enemy you are fighting is, none of them have a clue how to deal with Mercer or Heller performing a high jump. Universally they will run up to your location and then just stand there waiting for you to land. Both games are easily won by just spamming air attacks.
And to double the stupidity factor, the final boss in [PROTOTYPE 2] Alex Mercer is a Prototype himself, is seen to have the Whipfist power which is useful for grabbing targets out of the air, and specifically uses it on you if you try to jump out of the combat area - but if you jump straight up, he never thinks to use it, and instead runs into place underneath you like everyone else.
Soldiers have shorter sightlines (useful since they're better about noticing superhuman powers this time around) and will reposition themselves every few shots to make it harder to keep track of them. Fair enough, this works decently against Heller. But this breaks down when they go up against actual zombies; they will stand around idle with a hoard of infected roaming thirty feet away, and when the creatures finally get close enough to draw aggro the soldiers will shoot one and then charge into the middle of the pack.
Mercenaries 2: World in Flames is a crowning achievement in Artificial Stupidity. Frequently, enemy soldiers will run in front of vehicles, throw grenades at their own vehicles, crash said vehicles when at even the slightest deviation, attempt to plow their vehicles under your tank causing the game to assume the tank has run them over, drown themselves, run off of building ledges and generally kill themselves in a variety of amusing ways. This can be frustrating for numerous reasons, chief among them that Chinese RPG soldiers fire thermobaric rockets that do massive damage to you and the scenery. In fact, it is generally impossible to capture all the HVT's alive, because they will kill themselves or die at the hands of their subordinate troops.
The original was as bad, if not worse. Civilian vehicles would instant swerve into you even though you were in the other lane and in no way a threat (as far as they knew). Combatants would drive their jeeps into your tank, which was about as effective as you'd expect, and AI drivers would often run into the adamantium walls known as trees.
Dead Rising's survivors were, to put it bluntly, idiots. Half the time, they never followed you or would run off on their own, and giving them a weapon would sometimes result in them attacking you by accident. The sequelimproved the AI significantly. Then they slightly switch back to the way survivors were in the first game in Off the Record, the spin-off reimagining of said sequel, almost as if it's supposed to be some sort of twisted Call-Back due to Frank West being the protagonist again...
Yayandas: We are about to calibrate the newly installed, super-responsive inertial damper. You will never again feel the slightest shake, and never once be torn from your sleep, even if you are rammed head-on by a Xenon. Nopileos: Rrrr... do they do that? Yayandas: So one hears...
The Universe Trader Space Truckers you can use you augment your profits can be particularly braindead. In the vanilla game, they'll gleefully fly through a sector full of killer robots because a station under active attack has a great deal on bulk frozen hamburgers. They'll sometimes send messages to the player asking for help because the idiots filled their cargo hold with random crap that they can't get rid of. In early versions of X3: Reunion, your traders would also sometimes try to dogfight Space Pirates using their single rear turret if you gave them a weapon. These behaviors have been rectified or mitigated in a number of patches and Game Mods.
Egosoft deliberately tried to fix the idiotic pathfinding with X: Rebirth and it worked... mostly. The AI sometimes tries to fly through areas that are far too narrow for them to easily navigate through, leading to players finding Space Pirate ships wedged between cargo containers outside stations. Of course, they introduced even more AI issues, such as capital ship captains failing to refuel their ship, causing them to get stuck in space with no way to move.
The game can actually detect when it fucks up. If the Autopilots manages to plow head-on into an object at full speed, the ship's computer will declare " Autopilot epically failed."
The Sucellus, a massive destroyer toting a Fixed Forward-Facing Weapon spinal railgun, will attempt to get into broadsiding battles with anything it encounters. The Balor missile frigate has a similar problem in that the fragile, long-range bombardier will attempt to get into knife-fighting range with enemy capital ships so that it can use its token point defenses in combat. This behavior is rectified in a Game Mod.
Artificial Stupidity returns with a vengeance - but at random - in X4: Foundations. Ships will jump from being able to chase the player through a dense asteroid field, to losing their mind and seizing up when attempting to dock on a carrier, causing them to sit straight above the landing pad, upside down. Of note is that while the AI has no trouble with jumpgates and super-highways, the AI can't quite figure out how to enter a Trans-Orbital Accelerator and will frequently plow head-first into the side of it, start spinning around in circles then clip inside of it, before finally activating the accelerator and warping away. Of note is that the game had collision (hull) damage disabled in version 1.2. Before then, the game's Travel Drive combined with the infamous Auto-Pillock had a nasty tendency to ram smaller ships with stations at supersonic speeds.
Enemy mobs in Minecraft were quite stupid back in the early days of the game, and intentionally so according to Notch. They were programmed to do nothing more than walk in a straight line to reach the player and jump whenever a block stood in the way. This meant you could lead the infamous creepers to their deaths by tricking them to walk off a cliff or into a lava pool. A patch enhanced the mob AI and they no longer have their quirks.
The tame-able wolves update got a lot of flack when it was first introduced for the stupidity of the wolves. They would frequently get lost and de-spawn, or decide the shortest route between two points was a straight line right into a pool of lava.
Even now, pets of all sorts exhibit an alarming inability to recognize hazards. A horse left too close to a ravine may decide to wander straight off the edge, a cat being led though the Nether might try to walk right through a fire that's easily avoided, and a parrot might decide that the best time to leap off your shoulder and take off directly into your line of sight is the exact moment you fired an arrow at something.
Creepers still retain some artificial stupidity as an anti-frustration feature. They will not detonate and destroy your hard work unless they have a direct line of sight with you, meaning you can still have odd situations like groups of creepers gathered on a glass ceiling right above you or right next to your window outside, where all of them are unable to explode due to the completely transparent material somehow blocking their view.
Much of the Grand Theft Auto series has this, like NPCs crowding around scenes of carnage, even if the scene involves a flaming vehicle which might go off at any minute. At the same time, much of it's ambiguous whether it was a matter of programming or of deliberate portrayal. Given the nature of the GTA series, one should not rule out the possibility that they are portraying people that way on purpose.
Grand Theft Auto 2 features fellow carjackers who drive into cars already on the verge of exploding, civilians who run around in circles when a tank is driving through an alley they are in, and cops in a vehicle running over cops who are pursuing you on foot.
Random emergency vehicles will sometimes speed up the drive to the mafia don's house, slam headfirst into his garage door and continue to grind against it until their vehicles explode.
Everyone in Liberty City (apart from Claude) seems absolutely incapable of aiming a rocket launcher in any direction but down. And they actually seem to be aware of this, since if a pedestrian were to have a rocket launcher on them, they would run up to their target, and fire the rocket at the ground, killing both the target and themselves in the process. By San Andreas, this has been corrected so that pedestrians can fire rocket launchers at what is in front of them.
There's an elevated train system running around the map. Go to any of the stations and stand on the platform for a while. Within a minute or so there'll be a pile of bodies as NPCs spawn and casually walk on and off the platform onto the rails, even while the train is visibly inbound. And of course, the train never makes any attempt to slow down. To make this even funnier, there's an overlap in the collision detection of the train and the edge of the platform, where some NPCs stand while waiting for it. So even if no-one wanders onto the rails, the train is almost guaranteed to kill a couple of people at every station it stops at.
On the freeway, the AI can't seem to handle the speed at which it drives, resulting in a lot of accidents, even with no player intervention. If the player stays put long enough, massive pileups and riots inevitably occur and don't end until the player leaves the area.
Civilian drivers are actually dumb cars-on-rails until nudged, shot, or otherwise "awakened", at which point they become truly AI controlled and subject to proper physics (almost certainly for performance). In places, the map's "rails" seem to be set up wrong, and vehicles either accelerate or turn well beyond their actual capabilities, or outright spawn facing the wrong way then tween into place. Freeway pileups are usually a result of "rail" and "true" vehicles interacting badly. Planes are also tied to 'rails'. This frequently makes them disregard tall buildings, trees, hills (especially in San Fierro) or other particularly tall objects. And it. Is. Hilarious.
Also, pretty much every car that needs to make a right turn, is going to do so from the left lane, and vice versa for left turns. And that seems to be the most basic rule for the game's driving AI, but apparently it wasn't. It seems like the only realistic thing the other drivers do in the game is to high-tail it out of there when/if they hear gunshots.
The pedestrians walking on the streets are no better: If they notice that vehicle is coming at-full speed towards them, they will most likely jump out of its way to avoid being hit, however, there's also a chance that they may jump straight into the vehicle's path and get killed by the vehicle in question, even when it wasn't even coming straight towards them.
If you engage in a gang war, sometimes the enemy gang members will run down to the end of the block just to do a U-turn and run on the other side of the sidewalk. Sometimes this ranges to being miles away from the actual war zone but if the game is savvy enough, you're rewarded with the next wave or getting the area. Most of the time though you're stuck waiting around for them to come back because if you try to leave, the game pressures you to stay there.
Cops who in no way can get to their original car will usually run out onto the street and jack a civilian's car and drive off in that. Or more hilariously, a fellow officer's car.
Dubbed the suicidal photographer, this fellow stands at the edge of a cliff taking pictures of the city nearby. After he/she's done he/she just walks in a straight line into the water and dies. This happens every time.
Unlike the previous games, San Andreas averts Super Drowning Skills, and CJ can swim. However, this isn't extended to anyone else (barring recruited gang members and ally NPCs during missions), and if you have a Wanted level, there's no end to the line of cops that will jump in to get you and immediately drown.
NPCs on fire never have the ability to stop, drop and roll that the protagonist has. They often just run around until their health runs out and dies. In Grand Theft Auto: Vice City this extends to their use of molotovs as well - any hostile NPC that happens to obtain one and attempts to use it will simply drop it at their feet and set themselves on fire.
Enemies will attempt to use the cover system just as much as you do. While most of the time, enemies will use this cover effectively, they do on occasion take cover behind objects that are not very good at deflecting bullets or won't cover them effectively. So, you may spy a supposedly highly-trained N.O.O.S.E agent take cover behind a stack of cardboard boxes or a fire hydrant.
The AI used in the street races drives like a blind moron on drugs. It usually ends up overshooting corners because it doesn't slow down in time, plows right into other cars instead of trying to dodge and occasionally even manages to veer off a straight road.
Fly up in a helicopter with a high wanted level. Hover over a body of water (the ocean next to Francis International is a good example), and watch as the police attempt to pursue you. They seem to not understand the concept that they can not drive their car up to you, or that there is an ocean in the way. After a few minutes, half the local precinct will probably be bobbing about in the water like corks.
Ambulance drivers are completely out of their minds. They fly around at top speeds, overshoot turns, veer off at the slightest provocation, and crash into everything in their way. There are reports of ambulances mowing down five people in an attempt to resuscitate a guy who was punched in the face a few times.
If you get into a taxi, use a trainer to raise your wanted level and then tell the cab driver to hurry up, watch as the driver tries desperately (and usually surprisingly successfully) to dodge police cars, only to ram some immovable obstacle and stand there like an idiot while being pelted with gunfire. It usually takes a while for the driver to react and engage reverse, by which time there's typically a massive pileup of police vehicles behind the taxi preventing it from moving. Usually results in a dead driver and a mountain of cars desperately calling for a grenade tossed in their midst.
A glitch in the game allows you to enter a bar with a gun and come out drunk with it still in your hand, allowing you to fire it. For some reason, however, stumbling soused down the street, firing off your pistol like it's a Friday night in Tombstone makes the pedestrian AI go absolutely apeshit. Normally, when a gun is fired, most civilians will attempt to flee for cover, with only the occasional odd Badass Bystander attempting to put an end to you. However, firing a gun off while in your drunken state will make every male civilian on the block swarm you and try to pummel a lesson on safe firearms handling into your booze-soaked head.
AI in Grand Theft Auto V generally behaves well enough from the player's perspective; however, viewing a battle from above with mods or cheats reveals a few dumb moments.
Enemies can trip over things, including short ledges, railings, each other, or even a steep incline. It's not uncommon to see groups of enemies try to rush through a tiny doorway only to fall over each other in a pile.
Enemies will always rush blindly around a corner, no matter how many of their allies get wasted trying the same thing.
Sometimes an NPC will try to fire over cover that's a hair too tall, causing them to get stuck shooting into a wall. They will never move from this spot unless interrupted by something. Similarly, enemies will very rarely charge to dislodge an enemy and instead fire clip after clip into their indestructible cover, hoping to get a lucky shot.
The criminal groups you are allied with in Just Cause 2 don't seem to understand the concept of "strength in numbers" - faced with a propaganda trailer which will have no fewer than five Panauan soldiers patrolling around it at all times, your allies will gleefully send one guy to take it out. That one guy is usually shredded before he can exit his vehicle. Considering that the soldiers will then immediately turn their guns on you if you're too close, and that it happens every time you get anywhere near a trailer you might want to take out a bit more quietly, the only rational explanation is that the criminal groups are deliberately killing themselves to try and kill you too.
On the other side, for their amazing skill with firearms, Panauan soldiers cannot shoot you if there is a chain-link fence between you and them.
The Panauan police and military are also horrible drivers to a man. They will ignore everything but you in their attempts to bring you down. This means that they will charge suicidally at you in endless waves of highly explodable cars while you're parked in the middle of the road with a heavily armed APC blowing them up as they approach. Alternately, they will forget that they share the road with other vehicles, resulting in a motorcycle cop swerving around you to try and cut you off only to drift into oncoming traffic and unwittingly embed themselves into the grill of a passing lorry. They'll even forget that terrain exists and go flying off a cliff when you drive along the edge of a road that becomes a bridge. This contributes to the game's atmosphere rather than detracting from it, since the Panauan forces opposing Rico end up coming off as hilariously incompetent, which is already implied by their dialogue and other fluff text.
In Just Cause 3, if you destroy a bridge, NPC drivers will continue to drive as if it is there and plummet off the edge to their deaths at full speed, even if there should be plenty of time on the approach for them to see that the bridge is out.
In Saints Row 2, pedestrians will often jump to one side if they think the player will drive over them. However, at least as often as not, they throw themselves headlong onto the street, where they're likely to get run over by another NPC driver, or by the player if he was only barely on the sidewalk or if he was only taking a brief detour onto the sidewalk.
There are also certain roads that cabs seem to have... trouble with. More specifically, cabs tend to spawn at the end of a long, straight road... then turn around and start driving off in a random direction, taking the longest possible route to get to you. If they don't just explode. Or sometimes they'll spawn, but, for some reason, immediately shift into 'normal' NPC cabs which you can steal, rather than ride in. Also fits as a Good Bad Bug.
Airplane pilots seem to be a panicky lot in SR2, too. Shoot them once (with any gun) on the runway (which is the only place to really find NPC airplanes), and they'll immediately veer off the runway and crash into the closest bit of scenery, usually exploding in a giant fireball.
If you follow one of said planes into the air, you'll see it level off and fly unconcernedly right into a cliff, where it explodes. All planes from the airport explode on this cliff, at the same spot each time.
When you attempt to steal a vehicle that is also on your junkyard list, not only will the cops psychically know and immediately pounce on you, but the driver of said car will invariably panic and veer off the road in a random direction. The chance that this mad dash across pedestrian zones and off cliffs ends with the car despawning, crashing into a semi or disappearing into the ocean is proportional to the length of time you had to wait for it to show up in the first place. Oh, and if he hits something black and white and blue then you get wanted stars. It seems the only way to steal a car on your junkyard list without dealing with this is by shooting the driver.
Get a police car, drive on the rightmost lane and activate the siren. Cars in front of you will turn onto the sidewalk to avoid you. Cars in the middle lane will turn across your lane and stop there. For additional fun, try this on a highway bridge and watch the semis run the civilians off the road in their dash to get out of your way.
It gets less funny and more annoying if you try the same stunt in Saints Row: The Third, especially if you're trying to clear the road to go faster. Cars in front of you will completely fail to react to the siren until you've rear-ended them at top speed. Cars in a different lane, oncoming or not, will only turn into your lane so you crash into them.
The nuclear plant island should never be navigated by car. It is crammed with security vehicles that will do things like accelerate at high speed out of a side street and plow into you, rear-end you when you stop for a red light, or run over a pedestrian and proceed to chase you for manslaughter. It is virtually impossible to spend longer than a minute in this area at the wheel of a truck without getting wanted stars.
The driving AI in Saints Row: The Third seems to be even worse than its predecessor. Even when you're peacefully strolling through Steelport on foot without laying a finger on anyone, civilians will either be panicking or commenting on how they've narrowly escaped death because of how often cars collide with each other and run up on sidewalks.
In Endless Ocean Blue World, one of the ways you make money is by guiding clients around the various areas and showing them the creatures that live there. Clients will always head straight for you, regardless of obstacles. If they cannot do this, they "can't" find you, even if they ought to be able to see you, and you have to go back and find them, and swim in such a way as to keep that from happening. It's very easy to lose someone at the doorways of Valka Castle, or the pillars of the Ice Cavern's Hall of Radiance.
The allied ships AI in Age of Pirates 2: City of Abandoned Ships often interprets 'Sail Away' as 'Sail directly towards the most dangerous enemy ship regardless of wind direction or combat readiness'. Hilarity Ensues.
The AI is woeful in terms of driving. Hack the traffic lights. Hilarity Ensues. Every single time.
Raising a bridge during a car chase will net you a kick-ass jump, and leave your pursuers behind while they merrily drive over the edge of the raised bridge into the water.
Parking in the road can result in a pile-up of cars who won't drive around your car despite having a huge amount of space to go around it.
The vehicle driving AI can't handle being boxed in properly.
Vehicles will smash into dozens of other vehicles without the slightest bit of panic.
Going into the water can result in enemies unable to figure out how to jump over obstacles, blocking the rest of the people chasing you.
AI NPC's hanging out on the docks will fall into the water constantly.
NPC's will drop their phones and walk away if slightly bumped.
If you stand around two NPC's kissing, they will continue to make out while the woman will tell you to go away and eventually, while in the middle of french kissing the other NPC, will say "I will scream rape".
If you slightly bump someone about to call the cops with your car, they will stop. No-one else will ever try calling the cops even if you leave the general area.
The on-foot evasion AI will not go around obstacles at all, instead electing to 'parkour' over them, which can result in 50 year old construction workers jumping over traffic cones, or taking a route that is far slower than simply running around the obstacles.
In Unturned, the zombies benefit from The All-Seeing A.I. once they've spotted you, making it difficult to hide from them. However they can't jump or swim. You can hop through a broken window and watch a train of zombies run within arm's reach heading for the door. You can stand on top of a car or tread water just inches from a horde of zombies and all they'll do is mill around.
Ghost Recon Wildlands does not make for a flattering portrayal of the Bolivian motorist, with traffic jams quickly becoming the least of your worries. The worst offenders, however, are the rebels, who drive like absolute lunatics. While other drivers will stop if you stand in the road, with even Santa Blanca soldiers stopping their car to get out and shoot you, Rebels will happily run you down and drive off without a care in the world, rear-end a stopped car at near full-speed, and jump out of their trucks in the middle of a busy road at the slightest hint of imminent combat.
In Red Dead Redemption 2, AI controlled teammates are amazingly prone to running into your line of fire. To the point that it often seems like they're doing it on purpose. Line up a shot, watch as someone gets in your line of fire. Sidestep, watch as they move to get in front of you again. Sidestep the other way and watch as they again block your shot.
Ubisoft in general seems to not understand how to make civilian AI that can drive worth a damn. Of the myriad new dangers added to Far Cry 4, one of the worst is civilians in regular cars. Whereas the occasional civilian driver in Far Cry 3 had some idea of how to drive without murdering everything and everyone they find along the road, here any good driving sense was thrown over the mountain. They will drive at top speed no matter the circumstances or terrain, react too slowly (if at all) to things getting in their way, and in general seem to deliberately aim to run down anyone on the road - if they're not hitting you at every opportunity, they're running over your Golden Path allies or wandering Sherpa merchants whenever they find them.
Outer Wilds: In-universe, it's mentioned that Slate hasn't yet managed to get the auto-pilot's avoidance system to work properly. Which means that when activated, the autopilot will fly directly towards its set destination, regardless of what may be between the ship and said destination...
Hatchling:(Start of a new loop) The autopilot flew my ship directly into the sun! Slate: Had an exciting dream, did you? It's not exactly impossible for the autopilot to get you too close to the sun, but it's not like it'll try to take you there on purpose. Make sure the sun isn't between you and your destination when you engage autopilot, and you'll be fine.
This was given a Mythology Gag in Farnham's Legend, the novelization of the first game in a conversation between a pair of Teladi:Yayandas: We are about to calibrate the newly installed, super-responsive inertial damper. You will never again feel the slightest shake, and never once be torn from your sleep, even if you are rammed head-on by a Xenon.